#include <iostream>
#include <windows.h>
using namespace std;

volatile bool Sentinel = true;
int CriticalData = 0;

unsigned ThreadFunc1( void* pArguments ) {
   while (Sentinel)
      Sleep(0);   // volatile spin lock

   // CriticalData load guaranteed after every load of Sentinel
   cout << "Critical Data = " << CriticalData << endl;
   return 0;
} 

unsigned  ThreadFunc2( void* pArguments ) {
   Sleep(2000);
   CriticalData++;   // guaranteed to occur before write to Sentinel
   Sentinel = false; // exit critical section
   return 0;
}

int main_volatile(int argc,char **argv) {
   HANDLE hThread1, hThread2; 
   DWORD retCode;

   hThread1 = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)&ThreadFunc1,
      NULL, 0, NULL);
   hThread2 = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)&ThreadFunc2,
      NULL, 0, NULL);

   if (hThread1 == NULL || hThread2 == NULL)       {
      cout << "CreateThread failed." << endl; 
      return 1;
   }

   retCode = WaitForSingleObject(hThread1,3000);

   CloseHandle(hThread1);
   CloseHandle(hThread2);

   if (retCode == WAIT_OBJECT_0 && CriticalData == 1 )
      cout << "Success" << endl;
   else
      cout << "Failure" << endl;
}